FIG. 1 depicts top and side views of a portion of a conventional energy assisted magnetic recording (EAMR) transducer 10. For clarity, FIG. 1 is not to scale. The conventional EAMR transducer 10 is used in writing a recording media (not shown in FIG. 1) and receives light, or energy, from a conventional laser (not shown in FIG. 1). The conventional EAMR transducer 10 includes grating 32, a conventional waveguide 12 including a core 13 and cladding 11, conventional pole 30, and near-field transducer (NFT) 40. The conventional EAMR transducer 10 is shown with a laser spot 14 that is guided by the conventional waveguide 12 to the NFT 40 near the air-bearing surface (ABS). The NFT 40 focuses the light to magnetic recording media (not shown), such as a disk. Other components that may be part of the conventional EAMR transducer 10 are not shown.
In operation, light from the spot 14 is coupled to the conventional EAMR transducer 10 using the grating 32. The waveguide 12, which is shown as including a planar solid immersion mirror, cladding 11, and core 13, directs light from the grating 32 to the NFT 40. In other conventional EAMR transducers, the conventional waveguide 12 could take other forms. The direction of travel of the light as directed by the conventional waveguide 12 can be seen by the arrows 18 and 20. The NFT 40 focuses the light from the waveguide 12 and heats a small region of the conventional media (not shown). The conventional EAMR transducer 10 magnetically writes data to the heated region of the recording media by energizing the conventional pole 30.
Although the conventional EAMR transducer 10 may function, there are drawbacks. The trend in magnetic recording continues to higher recording densities. As a result, the track width is desired to be made smaller. The track width is defined by the pin width of the NFT 40. The smaller the width of the pin of the NFT 40, the higher the areal density. However, the efficiency and reliability of fabricating such NFTs may be limited. For example, to obtain an areal density of 2 Tb/in2, a thermal spot size of approximately thirty nanometers at full width half max may be used. Based on this, the pin of the NFT 40 for such a spot would be approximately thirty nanometers in width. In addition, there is currently approximately a twenty nanometer offset between the optical spot and thermal spot due to the thermal conduction of the media (not shown). The NFT 40 thus has a smaller width than the desired spot size. In the example above, an NFT 40 having a width of approximately ten nanometers is desired. This may be an extremely challenging requirement for fabrication. Further, such an NFT 40 may be more susceptible to failure due to overheating. In other contexts, such in photonic nanojets, a hemisphere may be used to provide a smaller spot. However, it is impractical to place a micron-scale dielectric sphere within the head structure and slider during fabrication. Accordingly, a mechanism for providing a small spot is still desired.